This invention relates to a circular knitting machine with a dual which includes a dial rotatable about an axis of rotation and having tricks for knitting implements, a stationary dial cam system, a device for feeding a lubricant to the dial arrangement and a collecting container for reception of lubricant escaping from the dial arrangement.
Circular knitting machines with a needle cylinder and optionally with a dial or a sinker ring are usually provided with lubricating devices, in order to feed a lubricant, especially oil, to the respective knitting implement carriers and the cam system parts associated therewith. The lubricant is introduced through nozzles, which are provided in the stationary cam system parts, to the knitting implement carriers and the knitting implements disposed therein, from whence it reaches inter alia the cam channels of the cam system parts provided to guide the knitting implements butts. It is further known to provide the needle cylinder region for example with numerous annular grooves to improve the distribution of the lubricant (DE-AS 1 635 931).
The effect which is achieved on the one hand in desired manner by the lubrication is that friction which arises is reduced and the concomitant wear is kept within bounds. On the other hand there is also an undesirable side effect, that excess lubricant gets into the knitwear produced with the circular knitting machine and then has to be washed out of this. Accordingly it would be ideal to feed only as much lubricant as is actually used by the knitting machine. However, it has only been possible to achieve this in the past on the one hand with a high technological outlay, because it is not possible to perform accurate enough metering with conventional lubricating devices. On the other hand, a certain excess of lubricant is not entirely undesirable, because other objectives can also be met with the lubricant. Among these are for example the dissipation of heat of friction or flushing away foreign bodies, e.g. yarn lint, out of the tricks of the knitting implement carriers or the cam system channels. A means of removing the excess proportion of the lubricant, which is not used in the circular knitting machine but which is desirable on account of these advantages, is therefore sought, so that the lubricant is caught by special means, particularly collecting containers, insofar as it runs off below in the knitting implement carriers, on account of gravity.
Experience shows that undesirably large amounts of lubricant get into the fabric made on the circular knitting machine, in spite of such measures, even when fine distribution and thus careful usage of lubricant is sought after through aerosol-like atomisation ("The Hosiery Trade Journal", February 1966, pp 127-131). This applies in particular to circular border knitting machines, i.e. circular knitting machines which are equipped with a dial, and is attributed to the fact that lubricant is transferred to the fabric by the knitting implements themselves. In order to avoid this problem it is accordingly known (U.S. Pat. No. 2,723,543) to use knitting implement carriers in which the actual carrying part (or needle bed) is separated from the knock-over part (or knock-over cam) by a recess disposed below the backs of the knitting implements and in which knitting implements are provided with strongly bent shank sections like webs which bridge over the recess at a sufficient distance. Interruption of the lubricant flow is to be achieved or the pumping action of the knitting implements is to be avoided by this. However, such devices have proved to be inadequate, especially in modern circular knitting machines operating at high speeds. Apart from this it is as a rule undesirable to provide knitting implements with the described shape. Accordingly it is generally the case in the use of modern circular border knitting machines basically to take into account contamination of the knitwear with lubricant and instead to enrich the lubricant with emulsifiers which improve the ability to wash it out and thus facilitate the removal of the lubricant from the knitwear. However, since such emulsifiers affect the lubricating quality and thus the lubricating characteristics of the lubricant adversely, they are undesirable in principle.